[R] lapply?

Toth, Denes toth.denes at ttk.mta.hu
Thu Nov 14 16:34:19 CET 2013


Hi,

the output of lapply() is a list; see ?lapply and ?sapply.

# if you know the length of your list in advance,
# this definition is better:
uu <- vector("list", 2)

# list elements
uu[[1]] <- c(1,2,3)
uu[[2]] <- c(3,4,5)


# some options to achieve what you want:
matrix(unlist(uu), 2, 3, T)
do.call(rbind, uu)
t(sapply(uu, I))


HTH,
  Denes


> Hi,
>
> I was trying to use lapply to create a matrix from a list:
>
> uu <- list()
> uu[[1]] <- c(1,2,3)
> uu[[2]] <- c(3,4,5)
>
> The output I desire is a matrix with 2 rows and 3 columns, so I try:
>
> xx <- lapply(uu,rbind)
>
> Obviously, I'm not doing something right, but what!?
>
> 	[[alternative HTML version deleted]]
>
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